I see what you're saying about the lack of clarity. It's possible the TTRPG puts too much on the GM to establish a standard of play. At some point, I may add an example of play to the rulebook to help with that. For now, at least, the pre-written adventure that can be downloaded demonstrates how a typical session of the TTRPG could be run.
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Just adding a bit about how arbitration is resolved in what types of scenarios would do a lot to clarify things. From your initial answer, it sounds like attribute choice for skill checks is player-driven, origins are decided democratically, and everything else is GM fiat. Which is not inherently a problem at all, but it's not stated anywhere.